What happened at the Big Bang?

This short video from the Royal Society explains What happened at the Big Bang. An ancient glow is shedding light on the beginning of the universe. There is a faint glow of ancient light that permeates our universe, called the Cosmic Microwave Background (CMB). Findings from the Planck space mission to detect variations in the CMB, reveals how they’re helping us to understand what happened in the first instants after the Big Bang.